Description:

Atom Transfer Radical Polymerization (ATRP) is a new method to prepare
well-defined polymers and copolymers using controlled radical polymerization.
ATRP is based on the transition metal catalysts which transfer reversibly
halogen atoms between active and dormant species. The robustness and efficiency
of ATRP is attractive for both industry and academia for preparation of
polymeric materials with novel properties for new applications.

There are three general objectives for the proposed research. The first one
is to design and synthesize new more efficient catalysts. The second one is to
extend ATRP to more environmentally friendly media, using either water or bulk
monomers (no VOCs). The third one is to prepare new environmentally benign
materials such as solventless coatings and recyclable polar thermoplastic
elastomers.

Approach:

The approach to reach the first objective (more efficient catalysts) will
include variation of ligands and metals used for ATRP as well as potential
immobilization of the catalyst on solid support. Using more reducing catalytic
systems should increase their efficiency and reduced their required amount.
Immobilization will facilitate recycling and reclamation of the catalyst.

Bulk polymerization have been already successful for many ATRP systems and
will be extended to new monomers. Water-borne ATRP systems require careful
choice of the catalyst which should be moisture insensitive and also surfactants
and stabilizers for heterogeneous systems. An additional challenge is to apply
emulsion conditions for the synthesis of block copolymers and end-functional
polymers.

Two systems have been chosen as examples of environmentally benign materials.
The first one is solventless coatings based on low viscosity hyperbranched and
multifunctional acrylic copolymers. The second system comprises recyclable polar
thermoplastic elastomers which will be reversibly physically crosslinked via
microphase separation rather than by irreversible chemical
vulcanization/crosslinking.

Expected Results:

It is anticipated that all three objectives will be reached within the proposed time leading to development of new more efficient catalysts which can be applied to water-borne media and allow the synthesis of new environmentally benign materials. We anticipate that all of these achievements will be subsequently used in academia and industry, benefiting the environment.

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.